Medium feeding device, image reading apparatus, and recording apparatus

ABSTRACT

A medium feeding device includes an imaging unit which images a medium tip end portion from a position of facing a face of the medium on a downstream side of a nipping position of the medium using a feeding unit and a separating unit; and a determining unit which determines whether or not there is transport disorder by evaluating a state of a boundary between a path member which forms a medium transport path and a medium tip end from image data obtained by the imaging unit, in which the determining unit sets a rectangular determining region including at least a part of the boundary with respect to the image data, and determines whether or not there is transport disorder based on a length of a boundary in the determining region.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/828,590 filed on Dec. 1, 2017. This applicationclaims priority to Japanese Patent Application No. 2016-256416, filedDec. 28, 2016. The entire disclosures of U.S. patent application Ser.No. 15/828,590 and Japanese Patent Application No. 2016-256416 areexpressly incorporated herein by reference.

BACKGROUND 1. Technical Field

The present invention relates to a medium feeding device which feeds amedium, and an image reading apparatus and a recording apparatusprovided with the medium feeding device.

2. Related Art

A recording apparatus represented by a printer, or an image readingapparatus represented by a scanner is provided with a feeding devicewhich automatically sends a sheet (also referred to as auto documentfeeder (ADF)), and is configured so as to perform automatic sending andreading of a plurality of sheets.

Here, in general, a feeding device is provided with a separatingmechanism which separates sheets; however, there is also a case in whichseparation is failed, and there is a concern of causing a breakage of adevice, when continuing sending of sheets in such a case. In JapanesePatent No. 4,773,384, a configuration in which a driven roller whichrotates following a sheet is provided, a rotation of the driven rolleris detected by a rotary encoder, and jamming is determined by detectinga movement amount of the sheet based on the detected result isdisclosed.

The jamming detecting unit in Japanese Patent No. 4,773,384 determinesjamming, using a rotation of the driven roller which comes into contactwith a sheet; however, when a frictional force between the driven rollerand a sheet decreases due to aging degradation, or the like, of thedriven roller, there is a concern that the driven roller may stop, andit may be erroneously detected as jamming, regardless of transporting ofthe sheet.

SUMMARY

An advantage of some aspects of the invention is to provide a mediumfeeding device which can detect transport disorder of a medium moreaccurately, and an image reading apparatus and a recording apparatuseach provided with the medium feeding device.

A medium feeding device according to a first aspect of the inventionincludes a medium mounting unit on which a medium is mounted; a feedingunit which feeds the medium from the medium mounting unit; a separatingunit which separates the medium between the feeding unit and theseparating unit by nipping the medium; an imaging unit which images amedium tip end portion from a position of facing a face of the medium ona downstream side of a nipping position of the medium using the feedingunit and the separating unit; and a determining unit which determineswhether or not there is transport disorder by evaluating a state of aboundary between a path member which forms a medium transport path and amedium tip end from image data obtained by the imaging unit.

In this configuration, since the medium feeding device is provided withthe imaging unit which images the medium tip end portion from theposition of facing the face of the medium on the downstream side of thenipping position of the medium using the feeding unit and the separatingunit, and the determining unit which determines whether or not there isa transport disorder by evaluating a state of the boundary between thepath member which forms the medium transport path and the medium tip endfrom image data obtained by the imaging unit, it is possible to morereliably determine the state of the medium tip end, and detect atransport disorder of the medium more accurately.

In the medium feeding device, the determining unit may set a rectangulardetermining region including at least a part of the boundary withrespect to the image data, and may determine whether or not there is thetransport disorder based on a length of the boundary in the determiningregion.

In this configuration, since the determining unit sets the rectangulardetermining region including at least a part of the boundary withrespect to the image data, and determines whether or not there is thetransport disorder based on the length of the boundary in thedetermining region, it is possible to determine whether or not there isthe transport disorder using an easy method.

In the medium feeding device, the determining unit determines whether ornot there is the transport disorder based on an angle of the boundary inthe determining region to a medium width direction as a directionorthogonal to a medium transport direction.

In the configuration, since the determining unit determines whether ornot there is the transport disorder based on the angle of the boundaryin the determining region to the medium width direction as the directionorthogonal to the medium transport direction, it is possible todetermine whether or not there is the transport disorder using an easymethod, and in particular, it is possible to easily detect skewing asone of the transport disorder.

In the medium feeding device, the determining unit may obtain averagedbrightness as a value in which brightness of a pixel group which goesalong the medium width direction as a direction orthogonal to the mediumtransport direction is averaged along the medium transport directionfrom the image data, and the determining unit may obtain a firstthreshold value as a threshold value with respect to the averagedbrightness for determining a present state of a medium, and a secondthreshold value as a threshold value for determining an absent state ofthe medium which is lower than the first threshold value, and maydetermine whether or not there is the transport disorder based on highsand lows of a value with high brightness with respect to the firstthreshold value, and highs and lows of a value with low brightness withrespect to the second threshold value, in the averaged brightness atboth ends of a determining range including at least a part of theboundary.

In the configuration, since the determining unit obtains averagedbrightness as a value in which brightness of a pixel group which goesalong the medium width direction as the direction orthogonal to themedium transport direction is averaged along the medium transportdirection from the image data, and determines whether or not there isthe transport disorder based on highs and lows with respect to the firstthreshold value of which brightness is high, and highs and lows withrespect to the second threshold value of which brightness is low, in theaveraged brightness at both ends of a determining range including atleast a part of the boundary, it is possible to easily recognize a stateof a medium tip end.

In the medium feeding device, in a case in which the determining unitdetermines that there is the transport disorder, the feeding unit may bestopped.

In the configuration, in a case in which the determining unit determinesthat there is the transport disorder, since the feeding unit is stopped,it is possible to avoid a failure of the device which is caused when thefeeding unit is operated in a state in which the transport disorderoccurred.

In the medium feeding device, a feeding roller which configures thefeeding unit, and is rotatably driven by a driving source, a separatingroller which configures the separating unit, and is rotated in a drivenmanner by being in contact with the feeding roller, and a detecting unitwhich detects a changing amount of a position of at least any one of thefeeding roller and the separating roller with respect to the otherroller may be provided.

In the configuration, since the detecting unit which detects a changingamount of a position of at least any one of the feeding roller and theseparating roller with respect to the other roller is provided, it ispossible to detect jamming of a medium by detecting the changing amountof a position when jamming of the medium occurs, and the feeding rolleror the separating roller is displaced.

In the medium feeding device, the detecting unit may include a drivenroller which rotates in a driven manner by being in contact with thefeeding roller or the separating roller as a target for detecting thechanging amount of a position, a roller support member which rotatablysupports the driven roller and can swing around a swing fulcrum, and anangle detecting sensor which detects a swing angle of the roller supportmember.

In the configuration, it is possible to configure the detecting unit ata low cost by making a structure thereof simple.

According to another aspect of the invention, there is provided an imagereading apparatus which includes a reading unit which reads a medium,and the medium feeding device according to the aspect.

In the configuration, it is possible to obtain an operational effectdescribed in the aspect, in the image reading apparatus.

According to a still another aspect of the invention, there is provideda recording apparatus which includes a recording unit which performsrecording on a medium, and the medium feeding device according to theaspect.

In the configuration, it is possible to obtain an operational effectdescribed in the aspect, in the recording apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is an external perspective view of a scanner in the invention.

FIG. 2 is a side view which illustrates a medium transport path of thescanner in the invention.

FIG. 3 is a block diagram of constituent elements which configure thescanner.

FIG. 4 is a diagram which schematically illustrates a medium transportpath of the scanner according to a first embodiment.

FIG. 5 is a diagram which schematically illustrates the medium transportpath of the scanner according to the first embodiment, and illustratesan imaging region using an imaging unit and a determining region.

FIG. 6 is a diagram which illustrates a determining region and an edgedetecting region in a normal transport state of a medium.

FIG. 7 is a diagram which illustrates a determining region and an edgedetecting region in a skewing state of a medium.

FIG. 8 is a diagram which illustrates a determining region and an edgedetecting region in a jamming state of the medium.

FIG. 9 is a flowchart when performing a transport control of a mediumusing an imaging unit according to the first embodiment.

FIG. 10 is a diagram which illustrates a determining region in a normaltransport state of a medium, and averaged brightness obtained from thedetermining region, in a second embodiment.

FIG. 11 is a diagram which illustrates a determining region in a skewingstate of a medium, and averaged brightness obtained from the determiningregion in the second embodiment.

FIG. 12 is a diagram which illustrates a determining region in a jammingstate of the medium, and averaged brightness obtained from thedetermining region in the second embodiment.

FIG. 13 is a side sectional view of a feeding roller and an angledetecting sensor according to a third embodiment.

FIG. 14 is a graph which illustrates an initial changing amount in thefeeding roller.

FIG. 15 is a side sectional view of the feeding roller and the angledetecting sensor in a case of an occurrence of jamming in the thirdembodiment.

FIG. 16 is a graph which illustrates a changing amount in a case of anoccurrence of jamming in the feeding roller.

FIG. 17 is a flowchart when performing a transport control of a mediumaccording to the third embodiment.

FIG. 18 is a side sectional view which illustrates one modificationexample of the third embodiment.

FIG. 19 is a side sectional view which illustrates another modificationexample of the third embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, embodiments of the invention will be described based ondrawings. The same configuration in each embodiment will be given thesame reference numerals, descriptions will be made only for the firstembodiment, and descriptions of the configuration will be omitted inembodiments thereafter.

FIG. 1 is an external perspective view of a scanner in the invention,FIG. 2 is a side view which illustrates a medium transport path of thescanner in the invention, FIG. 3 is a block diagram of constituentelements which configure the scanner, FIG. 4 is a diagram whichschematically illustrates the medium transport path of the scanneraccording to a first embodiment, and FIG. 5 is a diagram whichschematically illustrates the medium transport path of the scanneraccording to the first embodiment, and illustrates an imaging regionusing an imaging unit and a determining region.

FIG. 6 is a diagram which illustrates a determining region and an edgedetecting region in a normal transport state of a medium, FIG. 7 is adiagram which illustrates a determining region and an edge detectingregion in a skewing state of a medium, FIG. 8 is a diagram whichillustrates a determining region and an edge detecting region in thejammed state of the medium, FIG. 9 is a flowchart when performing atransport control of a medium using an imaging unit according to thefirst embodiment, and FIG. 10 is a diagram which illustrates adetermining region in a normal transport state of a medium, and averagedbrightness obtained from the determining region, in the secondembodiment.

FIG. 11 is a diagram which illustrates a determining region in a skewingstate of a medium, and averaged brightness obtained from the determiningregion in the second embodiment, FIG. 12 is a diagram which illustratesa determining region in a jammed state of the medium, and averagedbrightness obtained from the determining region in the secondembodiment, FIG. 13 is a side sectional view of a feeding roller and anangle detecting sensor according to a third embodiment, and FIG. 14 is agraph which illustrates an initial changing amount in the feedingroller.

FIG. 15 is a side sectional view of the feeding roller and the angledetecting sensor in a case of an occurrence of jamming in the thirdembodiment, FIG. 16 is a graph which illustrates a changing amount in acase of an occurrence of jamming in the feeding roller, FIG. 17 is aflowchart when performing a transport control of a medium according tothe third embodiment, FIG. 18 is a side sectional view which illustratesone modification example of the third embodiment, and FIG. 19 is a sidesectional view which illustrates another modification example of thethird embodiment.

In an X-Y-Z coordinate system illustrated in each figure, the Xdirection is a device width direction, and a sheet width direction, theY direction is a sheet transport direction in an image readingapparatus, the Z direction is a direction orthogonal to the Y direction,and a direction appropriately orthogonal to a face of a sheet which istransport. In addition, the +Y direction side in each figure is set tothe apparatus front face side, and the −Y direction side is set to theapparatus rear face side.

First Embodiment

The embodiment has a basic concept in which a tip end of a mediumtransported by an imaging unit provided in the medium transport path ofthe scanner 10 as the “image reading apparatus” is imaged, a transportstate of the medium is determined by evaluating a state of a boundarybetween a path member of the medium transport path and the tip end ofthe medium, from the obtained image data, and a necessary transportcontrol is performed.

Regarding Image Reading Apparatus

When referring to FIGS. 1 and 2, the scanner 10 is provided with a lowerunit 12, a higher unit 14, a cover portion 16, and a discharging tray18. In the embodiment, though it is not illustrated, the higher unit 14is rotatably attached to the lower unit 12 by setting the downstreamside in a sheet transport direction to a rotation fulcrum.

The cover portion 16 is rotatably attached to the lower unit 12 on ahigher part of the rear face side of the lower unit 12. The coverportion 16 can obtain a non-feeding state (not illustrated) which coversa higher part of the higher unit 14 and a feeding port 20, and a feedingstate of rotating to the apparatus rear face side, as illustrated inFIG. 1, and opening the feeding port 20. In addition, the rear face ofthe cover portion 16 functions as a medium mounting portion 16 a onwhich the medium P is mounted in the feeding state as illustrated inFIG. 1.

A discharging port 24 from which a medium P is discharged is provided onthe apparatus front face side of the lower unit 12. In addition, thelower unit 12 is provided with a discharging tray 18 which can be pulledout from the discharging port 24 toward the apparatus front face side.The discharging tray 18 can obtain a state of being received in a baseportion of the lower unit 12 (not illustrated), and a state of beingpulled out to the apparatus front face side (refer to FIG. 1). Thedischarging tray 18 is configured of a plurality of tray members whichare connected, in the embodiment, and a length to be pulled out from thedischarging port 24 can be adjusted according to a length of the mediumP which is discharged.

Regarding Medium Transport Path In Scanner

Subsequently, a medium transport path 26 in the scanner 10 will bedescribed with reference to FIGS. 2 to 4. In FIG. 2, in the lower unit12 and the higher unit 14, only exteriors of housings thereof aredenoted by a virtual line. A thick solid line attached with a mark P inFIG. 2 denotes a guiding path of a medium transported along a mediumtransport path 26 in the scanner 10.

In the embodiment, the medium P which is set in the feeding port 20 issupported by the rear face of the cover portion 16 in a posture of beingrotated on the apparatus rear face side with respect to the lower unit12, that is, supported by the medium mounting portion 16 a, and ismounted thereon. A plurality of the medium P can be set in the feedingport 20. A mounting unit detecting sensor 28 is provided in the mediummounting portion 16 a. The mounting unit detecting sensor 28 isconfigured as a contact sensor including a lever, or the like, or anoptical sensor, as an example, and transmits a detecting signal to acontrol unit 30, which will be described later, when the medium P is seton the medium mounting portion 16 a. In addition, it is possible to setthe plurality of mediums P on the medium mounting portion 16 a.

In the embodiment, a pair of edge guides 22 are provided in the mediummounting portion 16 a, as illustrated in FIG. 4. The edge guides 22 areconfigured so as to move in a direction of being close to each other ora direction of being separated from each other in the device widthdirection in FIG. 4. In addition, when the medium P is set in the mediummounting portion 16 a, a guide face 22 a of the edge guide 22 comes intocontact with a side portion of the medium P in the device widthdirection, moves the edge guide 22 to a position of regulating aposition of the medium P in the device width direction, and holds theside portion of the medium P. In this manner, the edge guide 22 guidesfeeding of the medium P. The edge guides 22 in FIG. 4 show a state ofbeing farthest from each other in the device width direction, that is,in the width direction of the medium P.

Here, a medium transport region W is set as a region between guide faces22 a of the pair of edge guides 22 in a state of being farthest fromeach other in the device width direction, when referring to FIG. 4.Specifically, the medium transport region W is set to a width of themedium P with a maximum size which can be fed in the scanner 10.

In the medium P mounted on the medium mounting portion 16 a, a medium Pmounted on the lowest portion is fed to the downstream side in thefeeding direction using a feeding roller 34 as a “feeding unit” which isrotatably driven by a feeding driving motor 32 (refer to FIG. 3). Asillustrated in FIG. 4, two feeding rollers 34 are provided with aninterval in the device width direction, as an example. The outerperipheral face of the feeding roller 34 is configured of a highfriction material (for example, elastomer such as rubber, or the like).

A mark G in FIG. 2 denotes a bunch of medium P mounted (set) on themedium mounting portion 16 a. A tip end of the bunch of medium G is heldat a feeding standby position (position in FIG. 2) using a stopper (notillustrated), before a start of feeding, and entering between thefeeding roller 34 and a separating roller 36 which will be describedlater is regulated.

As illustrated in FIG. 2, the separating roller 36 as a “separatingunit” is provided at a position of facing the feeding roller 34. Asillustrated in FIG. 4, two separating rollers 36 are provided atpositions corresponding to the feeding roller 34 in the device widthdirection. The separating rollers 36 are provided in a state of beingurged with respect to the feeding roller 34 using an urging unit (notillustrated). In addition, the separating roller 36 is rotatably drivenin a direction opposite (counterclockwise direction in FIG. 2) to arotation direction of the feeding roller 34 (counterclockwise directionin FIG. 2, that is, direction of sending medium to downstream side)using a transport driving motor 38 (refer to FIG. 3). The outerperipheral face of the separating roller 36 in the embodiment isconfigured of the high friction material (for example, elastomer such asrubber, or the like), similarly to the feeding roller 34.

In addition, in the embodiment, a torque limiter 40 is provided in theseparating roller 36. The separating roller 36 is configured so as toreceive a driving torque of the transport driving motor 38 through thetorque limiter 40.

Here, when rotation torque received from the feeding roller 34 exceedslimit torque of the torque limiter 40, the separating roller 36 isseparated from a driving system of the transport driving motor 38 usingthe torque limiter 40, and rotates in accordance with the feeding roller34 (clockwise direction in FIG. 2).

When feeding of the medium P is started, and the plurality of mediums Penter between the feeding roller 34 and the separating roller 36, theseparating roller 36 is not able to receive rotation torque from thefeeding roller 34, and the rotation performed in accordance with thefeeding roller 34 stops. In addition, the separating roller 36 startsrotating in the direction opposite to the feeding roller 34(counterclockwise direction in FIG. 2) by receiving a driving force ofthe transport driving motor 38 through the torque limiter 40. In thismanner, mediums P on the top (medium P to be prevented from doublefeeding) except for the lowest medium P to be fed does not receive atransport force for proceeding to the downstream side, and returns tothe upstream side in the transport direction due to the rotation of theseparating roller 36. In this manner, double feeding of the medium P isprevented. In addition, the lowest medium P to be fed proceeds to thedownstream side due to a transport force which is received from thefeeding roller 34, since the medium P is in direct contact with thefeeding roller 34.

Subsequently, in the medium transport path 26, a first medium detectingsensor 42 which detects feeding of the medium P is provided on thedownstream side of the feeding roller 34 and the separating roller 36.In addition, as illustrated in FIG. 4, the first medium detecting sensor42 is disposed in the transport region W of the medium P with a maximumsize which can be fed, in the device width direction of the mediumtransport path 26, as an example. The first medium detecting sensor 42is provided with a light emitting portion 42 a and a light receivingportion 42 b. The light emitting portion 42 a and the light receivingportion 42 b are disposed at positions facing each other by interposingthe medium transport path 26 therebetween. In addition, it is configuredso that the medium P is detected when the medium P blocks off detectinglight from the light emitting portion 42 a, at a time of transportingthe medium P to the medium transport path 26. In addition, whendetecting the medium P, the first medium detecting sensor 42 transmits adetecting signal to the control unit 30.

An imaging unit 44 is provided on the downstream side of the feedingroller 34 and the separating roller 36. As an example, the imaging unit44 is provided at the higher unit 14 side and a center portion in thedevice width direction in the medium transport path 26, and is disposedso as to image the path member 46 on the lower unit 12 side which formsa part of the medium transport path 26, more specifically, the centerportion in the device width direction of the medium transport path 26.

The imaging unit 44 starts imaging of the medium transport path 26 whendriving of the feeding roller 34 is started. In addition, the imagingunit 44 sends the imaged image data to the control unit 30 as the“determining unit”. In addition, the imaging unit 44 in the embodimentis an area sensor in which an imaging element such as a CCD or a CMOS,as an example, is disposed in a planar shape.

When referring to FIG. 2 again, a double feeding detecting sensor 48which detects double feeding of the medium P is disposed on thedownstream side of the first medium detecting sensor 42 and the imagingunit 44 in the transport direction, in the medium transport path 26. Inaddition, as illustrated in FIG. 4, the double feeding detecting sensor48 is disposed in the medium transport region W in the device widthdirection. In the embodiment, the double feeding detecting sensor 48 isconfigured as an ultrasonic sensor which is provided with a speakerportion 48 a and a microphone portion 48 b. In addition, the doublefeeding detecting sensor 48 is configured so as to oscillate ultrasonicwave toward the medium P from the speaker portion 48 a through themedium transport path 26, and detects a reflected sound from the mediumP in the microphone portion 48 b. In the embodiment, the double feedingdetecting sensor 48 is configured so as to also detect a type of papersuch as thick paper, not only double feeding of the medium P using afrequency of the reflected sound.

A pair of transport rollers 50 is provided on the downstream side of thedouble feeding detecting sensor 48 in the transport direction in themedium transport path 26. In addition, as illustrated in FIG. 4, twopair of transport rollers 50 (transport driving rollers 50 a) areprovided in the device width direction with an interval. In addition,the pair of transport rollers 50 is provided with a transport drivingroller 50 a, and a transport driven roller 50 b which rotates in adriven manner with respect to the transport driving roller 50 a. In theembodiment, the transport driving roller 50 a is rotatably driven, usingthe transport driving motor 38.

A second medium detecting sensor 52 is provided on the downstream sideof the pair of transport rollers 50 in the transport direction, in themedium transport path 26. The second medium detecting sensor 52 isconfigured as a contact sensor including a lever, as an example. Inaddition, when the medium P is transported along the medium transportpath 26, the lever of the second medium detecting sensor 52 rotates onthe downstream side in the transport direction, by being pressed by atip end of the medium P (refer to two-dot dashed line in FIGS. 2 and 4).In this manner, the second medium detecting sensor 52 detects the mediumP. In addition, the second medium detecting sensor 52 transmits adetecting signal to the control unit 30 when the medium P is detected.

An image reading unit 54 as the “reading unit” is provided on thedownstream side of the second medium detecting sensor 52. Here, theimage reading unit 54 is provided with a first reading unit 54A which isprovided in the lower unit 12 so as to face the lower face of the mediumP which is transported along the medium transport path 26, that is, afirst face, and a second reading unit 54B which is provided in thehigher unit 14 so as to face a top face of the medium P transportedalong the medium transport path 26, that is, a second face. In theembodiment, the first reading unit 54A and the second reading unit 54Bare configured as a “reading unit”, and is configured as a contact typeimage sensor module (CISM), as an example.

The medium P is discharged from a discharging port 24 by being nipped bya pair of discharging rollers 56 which is located on the downstream sideof the image reading unit 54 in the transport direction, after an imageon at least one face of the first face and the second face of the mediumP is read in the image reading unit 54.

In the embodiment, the pair of discharging rollers 56 is provided with adischarging driving roller 56 a, and a discharging driven roller 56 bwhich rotates in a driven manner with respect to the discharging drivingroller 56 a. In the embodiment, the discharging driving roller 56 a isrotatably driven by the transport driving motor 38. In addition, thetransport driving roller 50 a and the discharging driving roller 56 aare configured so as to be rotatably driven by the transport drivingmotor 38 as a common driving source; however, it may be a configurationin which the transport driving roller and the discharging driving rollerare rotatably driven, individually, using an individual driving source.

The control unit 30 (refer to FIG. 2) is provided inside the lower unit12. The control unit 30 in the embodiment is configured as an electriccircuit provided with a plurality of electronic components. The controlunit 30 controls a feeding driving motor 32 which rotatably drives thefirst reading unit 54A, the second reading unit 54B, and the feedingroller 34 by receiving detecting signals of the mounting unit detectingsensor 28, the first medium detecting sensor 42, the double feedingdetecting sensor 48, and the second medium detecting sensor 52, and thetransport driving motor 38 which rotatably drives the transport drivingroller 50 a and the discharging driving roller 56 a. In addition, thecontrol unit 30 controls the imaging unit 44 to start imaging along witha start of driving of the sheet feeding roller 34.

The control unit 30 as an example is configured so as to controltransporting of the medium P, and an image reading operation in thescanner 10. In addition, the control unit 30 may control operationswhich are necessary at a time of executing a medium reading operation inthe scanner 10, based on an instruction from the outside (PC, or thelike).

In the embodiment, as an example, the medium mounting portion 16 a, thefeeding roller 34, the separating roller 36, the imaging unit 44, andthe control unit 30 configure a medium feeding device 58. Regardingtransport control of medium using imaging unit

Subsequently, a transport control of the medium P using the imaging unit44 will be described with reference to FIGS. 4 to 9. First, whenreferring to FIGS. 4 and 5, the imaging unit 44 is configured so as toimage the medium transport path 26, and a part of the path member 46 ofthe lower unit 12 from the higher unit 14 side. Specifically, theimaging unit 44 is configured so as to image the inside of an imagingregion R1 which is surrounded with a dashed line. According to theembodiment, a rectangular segmented region R2 (refer to one-dot dashedline) which determines a boundary between a tip end portion PF of themedium P and the path member 46 is provided in the imaging region R1. Inaddition, the hatched portion in FIGS. 6 to 8 denotes a region of thepath member 46 which is imaged.

As illustrated in FIG. 5, the medium P is fed by the feeding roller 34from the medium mounting portion 16 a to a position which gets out of anipping point between the feeding roller 34 and the separating roller 36in the medium transport path 26. In this manner, the tip end portion PFof the medium P reaches the inside of the imaging region R1 of theimaging unit 44, and the inside of a segmented region R2. In addition,the imaging unit 44 transmits image data in a state in which the tip endportion PF of the medium P reached the inside of the segmented region R2to the control unit 30.

Hereinafter, a transport control in a case in which the medium P isnormally transported, and a case in which there is transport disorderwill be further described with reference to FIGS. 6 to 9. As illustratedin FIG. 9, the control unit 30 receives a start signal of an imagereading job as step S1. In addition, the control unit 30 causes thefeeding roller 34, the separating roller 36, and the transport drivingroller 50 a to start feeding of the medium P by rotatably drivingthereof as step S2. In addition, the control unit 30 starts imagingusing the imaging unit 44 along with a start of driving of the feedingroller 34 as step S3.

Here, when the medium P is transported to the downstream side in thetransport direction in a normal state by passing through the nippingpoint between the feeding roller 34 and the separating roller 36, thetip end portion PF of the medium P reaches the segmented region R2 inthe imaging region R1, as illustrated in FIG. 6.

The control unit 30 determines whether or not the tip end portion PF ofthe medium P reaches the segmented region R2 based on the image datatransmitted from the imaging unit 44, as step S4.

Whether or not the tip end portion PF of the medium P reached thesegmented region R2 may be determined based on whether or not apredetermined time has passed after starting of driving of the feedingroller 34, for example, may be determined based on a detection of thetip end portion PF using the first medium detecting sensor 42, or may bedetermined based on a change in image data transmitted from the imagingunit 44.

In addition, the control unit 30 sets the segmented region R2 which isillustrated in FIGS. 6 to 8, as step S5. The segmented region R2 is aregion with a predetermined width in the sheet transport direction, andis a region in which a center portion of the tip end portion PF in thesheet width direction is included, as an example. The control unit 30evaluates a state of the tip end portion PF in the segmented region R2.

More specifically, in the embodiment, light is radiated to the imagingregion R1 using a light source (not illustrated), in order to make animage in the in the segmented region R2 preferable. In addition,reflected light of the imaging region R1 in a state in which the tip endportion PF of the medium P is located in the segmented region R2 isreceived by an imaging element of the imaging unit 44, and the controlunit 30 performs predetermined processing with respect to the image datain the segmented region R2 in the imaging region R1 which is obtained bythe imaging unit 44.

More specifically, a detecting intensity of the imaging element whichreceives reflected light from the medium P becomes stronger than adetecting intensity of an imaging element which receives reflected lightfrom the path member 46, and of which brightness is high. That is, inimage data imaged by the imaging unit 44, brightness of a portioncorresponding to the medium P is high, and brightness of a portioncorresponding to the path member 46 is low. The control unit 30 canclearly determine a boundary between the tip end portion PF of themedium P and the path member 46 in the image data in the segmentedregion R2 which is illustrated in FIG. 6, that is, the edge.

In addition, in a case in which the tip end portion PF of the medium Pis detected in the segmented region R2, the control unit 30 sets adetermining region R3, as described above, as step S5, and determineswhether or not an edge angle of the tip end portion PF is smaller than adetermining angle in the determining region R3, and whether or not alength of the edge of the tip end portion PF is a determining length ormore (step S6).

First, determining of the edge angle of the tip end portion PF will bedescribed. The control unit 30 determines whether or not an inclinedangle of the edge (edge angle: angle 0 in FIG. 7) with respect to awidth direction (X axis) of the determining region R3 is smaller than apreset determining angle. In addition, in a case in which the edge angleθ is smaller than the determining angle, it is determined whether atleast skewing does not occur, or the skewing falls in an allowablelevel, even when the skewing occurred, and subsequently, the edge lengthof the tip end portion PF is determined.

In a case in which the edge angle θ is the determining angle or more,that is, the degree of skewing exceeds the allowable level, the processproceeds to step S8 (which will be described later).

FIG. 6 illustrates an example in a case in which the medium P isnormally transported, that is, without causing skewing, and FIG. 7illustrates an example in a case in which skewing occurred. In addition,the edge of the tip end portion PF is formed in a stepwise shape becauseof a resolution of the imaging unit 44 (number of pixels).

Subsequently, though it depends on a calculating method of the edgeangle θ, for example, in a case in which a tip end of a sheet isdeformed due to trapping of the tip end of the sheet, not skewing (stateof being jammed or state before being jammed), as illustrated in FIG. 8,there is also a case in which the edge angle θ in the determining regionR3 which is calculated falls in the determining angle, as a result.

Accordingly, the control unit 30 also determines the edge length, inaddition to the determination of the edge angle θ in the determiningregion R3. Whether the edge length is good or bad is determined by asize of the edge length of the tip end portion PF with respect to alength W1 in the width direction of the determining region R3(hereinafter, referred to as “edge determining length W1”).

For example, in a case in which the medium P is normally transportedinto the determining region R3 without skewing or jamming, asillustrated in FIG. 6, the edge length of the tip end portion PF becomesat least W1, or more than W1.

However, in the skewing state as illustrated in FIG. 7, or the jammingstate as illustrated in FIG. 8, the edge length of the tip end portionPF (W2 in FIGS. 7, and W3 in FIG. 8) becomes the edge determining lengthW1 or less. Accordingly, in this case, it is determined as transportdisorder, and process proceeds to step S8 (which will be describedlater).

By also determining the edge length, in addition to the edge angle θ ofthe tip end portion PF in the determining region R3, in this manner, itis possible to more reliably detect transport disorder.

In addition, in a case in which both of the edge angle θ of the tip endportion PF and the edge length in the determining region R3 are good,the process proceeds to step S7, and the control unit 30 continuestransporting of the medium P to the downstream side in the transportdirection. In addition, when the tip end portion PF of the medium P isdetected by the second medium detecting sensor 52, the control unit 30stops a rotation of the feeding roller 34, and starts image reading ofthe medium P in the image reading unit 54. In addition, the control unit30 ends the image reading job by stopping the rotation of pair oftransport rollers 50 and the pair of discharging rollers 56, aftertransporting the medium P by a predetermined amount, after detecting ofthe rear end of the medium P by the second medium detecting sensor 52.

Meanwhile, in a case of the transport disorder as illustrated in FIG. 7or 8, the control unit 30 stops a rotation of the feeding roller 34 instep S8, and stops transporting of the medium. In addition, the controlunit 30 ends the image reading job by emitting an error signal in stepS9.

As described above, the control unit 30 can accurately determine thetransport disorder, immediately after feeding by the feeding roller 34,in a case in which skewing or jamming occurred in the medium P, that is,in a case in which transport disorder occurred, based on the image dataimaged by the imaging unit 44, and as a result, it is possible to reducea damage of the medium P, since feeding of the medium P is stoppedearly.

Second Embodiment

Subsequently, a transport control of the medium P according to a secondembodiment will be described with reference to FIGS. 10 to 12. Adifference in the embodiment from the above described first embodimentis the determining method of the transport disorder illustrated in stepS6 in FIG. 9, and since the other feeding controls are the same as thosein the above described first embodiment, descriptions thereof will beomitted.

In the embodiment, though it will be described in detail later, broadly,in the image data in the segmented region R2, averaged brightness as avalue in which brightness of a pixel group is averaged along the devicewidth direction (medium width direction) is obtained along the mediumtransport direction. In addition, whether or not there is transportdisorder of the medium P is determined based on a determination onwhether or not a high value in the averaged brightness is higher thanthe first threshold value L1 as a threshold value for determining astate in which the medium is present, and a determination on whether ornot a low value in the averaged brightness is lower than the secondthreshold value L2 as a threshold value for determining a state in whichthe medium is absent. In addition, the second threshold value L2 is setto be lower than the first threshold value L1.

When describing while referring to drawings, in the embodiment, thecontrol unit 30 averages brightness of a pixel group on the same linealong the device width direction (medium width direction) with respectto image data in the segmented region R2, as illustrated in FIG. 10, andobtains averaged brightness. This process is performed along the mediumwidth direction. Here, the left side of a paper face in FIGS. 10 to 12denotes a state of the segmented region R2 imaged by the imaging unit44, and the graph on the right side of the paper face denotes averagedbrightness obtained based on the image data in the segmented region R2.In addition, the hatched portion in the segmented region R2 in FIGS. 10to 12 denotes a region of the imaged path member 46.

In FIGS. 10 to 12, the first threshold value L1 is set to a value ofbrightness which can determine a state in which a medium is present. Inaddition, a value L3 with high brightness (value denoting presence ofsheet) has brightness higher than the first threshold value L1.Meanwhile, the second threshold value L2 is set to a value withbrightness which can determine an absent state of a medium. In addition,the value L3 with low brightness (value denoting absent state of sheet)has brightness lower than the second threshold value L2.

FIG. 10 illustrates a normal transport state, and in the normaltransport state, a line denoting averaged brightness becomes a straightline which directly erects (falls down) at the position of the tip endportion PF.

In this manner, at a position Y1 on the upstream side in the mediumtransport direction in the determining region R3, averaged brightnessexceeds the first threshold value L1, and becomes L3. In addition, at aposition Y2 on the downstream side in the transport direction, averagedbrightness is lower than the second threshold value L2, and becomes L4.In this manner, the control unit 30 can determine that it is a normaltransport state.

Meanwhile, in a case in which the medium P is skewed as illustrated inFIG. 11, a line denoting averaged brightness is inclined.

In this manner, averaged brightness is lower than the first thresholdvalue L1 at the position Y1 on the upstream side in the medium transportdirection in the determining region R3, and averaged brightness exceedsthe second threshold value L2 at the position Y2 on the downstream sidein the transport direction. In this manner, the control unit 30 candetermine that transport disorder has occurred.

In addition, in a case in which jamming occurs as illustrated in FIG.12, a line denoting averaged brightness is inclined, and the inclinationbecomes steep compared to that in the case of skewing illustrated inFIG. 11.

In this manner, averaged brightness exceeds the first threshold value L1at the position Y1 on the upstream side in the medium transportdirection in the determining region R3; however, averaged brightnessexceed the second threshold value L2 at the position Y2 on thedownstream side in the transport direction. In this manner, the controlunit 30 can determine an occurrence of transport disorder.

As described above, the control unit 30 performs averaging of a value ofbrightness based on image data imaged by the imaging unit 44, and canaccurately determine transport disorder immediately after feeding by thefeeding roller 34, by comparing the averaged brightness with the firstthreshold value L1 and the second threshold value L2. As a result, it ispossible to reduce a damage of the medium P since feeding of the mediumP is stopped early.

In addition, the control unit 30 in the above described embodimentdetermines transport disorder by comparing averaged brightness at theposition Y1 on the upstream side in the medium transport direction andthe position Y2 on the downstream side in the transport direction withthe first threshold value L1 and the second threshold value L2; however,transport disorder may be determined based on an inclination of astraight line of averaged brightness in the determining region R3, byobtaining thereof.

Modification Example of First Embodiment and Second Embodiment

In the embodiment, the imaging unit 44 is disposed at the center portionin the device width direction of the medium transport path 26; however,instead of this configuration, the imaging unit 44 may be disposed atportions other than the center portion in the device width direction inthe medium transport path 26. According to such a configuration, it ispossible to reliably detect jamming which occurs at portions other thanthe center portion in the device width direction in the medium transportpath 26.

Third Embodiment

Subsequently, a third embodiment will be described with reference toFIGS. 13 to 17. In the embodiment, the medium feeding device 58 furtherincludes a detecting unit 60. As illustrated in FIG. 13, the detectingunit 60 is provided with a driven roller 62 which rotates in a drivenmanner by being in contact with the feeding roller 34, a roller supportmember 64 which supports the driven roller 62, an angle detecting sensor66 which detects a swing angle of the roller support member 64, and anurging unit 68 which urges the driven roller 62 toward the feedingroller 34. In addition, the urging unit 68 is configured of a coilspring, as an example.

Here, when the feeding roller 34 rotates, also the driven roller 62starts rotating in a driven manner. At this time, in the feeding roller34, a position on the surface of the roller is changed due to eccentric,abrasion of the roller surface, or the like. Accordingly, a position ofthe driven roller 62 is also changed following a positional change ofthe feeding roller 34. In this manner, the roller support member 64which supports the driven roller 62 swings. The angle detecting sensor66 detects an amount of change in position of the feeding roller 34through a swing of the roller support member 64.

When referring to FIG. 17, a power supply of the scanner 10 is set to anON state, as step S10. In addition, the control unit 30 rotatablydriving the feeding roller 34 as step S11, and detects an initialchanging amount of the changing amount of a position of the feedingroller 34 using the angle detecting sensor 66. Subsequently, the controlunit 30 receives a start signal of the image reading job as step S12. Inaddition, the control unit 30 causes feeding of the medium P to bestarted, by rotatably driving the feeding roller 34, the separatingroller 36, and the transport driving roller 50 a as step S13.

In addition, the control unit 30 determines whether or not the changingamount of a position of the feeding roller 34 when feeding the medium Pis a threshold value L5 or less as step S14. Here, when referring toFIG. 14, the threshold value L5 is set to be larger than a changingamount of a position when the medium P is normally fed by the feedingroller 34. When the medium P is normally fed by the feeding roller 34,as illustrated in FIG. 14, the control unit 30 proceeds to step S15,since the changing amount of a position of the feeding roller 34 issmaller than the threshold value L5. In addition, in a case in which thechanging amount of a position of the feeding roller 34 is the thresholdvalue L5 or more, the process proceeds to step S16 which will bedescribed later.

In addition, the control unit 30 continues transporting of the medium Pto the downstream side in the transport direction in step S15, and endsthe image reading job after performing image reading of the medium P inthe image reading unit 54.

Meanwhile, as illustrated in FIG. 15, in a case in which jamming occurswhen the feeding roller 34 transports the medium P, a position of thefeeding roller 34 is changed in a direction separated from theseparating roller 36. In addition, the change of the feeding roller 34is detected by the angle detecting sensor 66. As illustrated in FIG. 16,when the medium P causes jamming, a changing amount of a position of thefeeding roller 34 exceeds the threshold value L5. In addition, a portionwith a dashed line in FIG. 15 denotes a position of the feeding roller34 in the initial state.

Accordingly, in a case in which the control unit 30 determines that thechanging amount of a position of the feeding roller 34 exceeds thethreshold value L5 in step S14, the process proceeds to step S16. Inaddition, the control unit 30 stops a rotation of the feeding roller 34.Subsequently, the control unit 30 emits an error signal as step S17, andstops the image reading job.

In the embodiment, since the change amount of the feeding roller 34 isdirectly monitored, it is possible to immediately stop a rotation of thefeeding roller 34 in a case in which disorder occurs in feeding of themedium P, and accordingly, it is possible to further reduce a damage ofthe medium P. In addition, in the embodiment, since an initial changingamount of the feeding roller 34 is read at a time of power ON of thescanner 10, it is possible to monitor an amount of abrasion of thefeeding roller 34, and suppress erroneous detecting when the feedingroller 34 is worn out.

Modification Example of Third Embodiment

(1) In the embodiment, it is configured so that a changing amount of aposition of the feeding roller 34 is detected by the detecting unit 60;however, it may be a configuration in which a changing amount of aposition of the separating roller 36 is detected, instead of theconfiguration. Specifically, a configuration in which the detecting unit60 is provided on the separating roller 36 side, as illustrated in FIG.18, the driven roller 62 is caused to come into contact with theseparating roller 36, and a changing amount of a position of theseparating roller 36 is detected by the angle detecting sensor 66 may beadopted. With such a configuration, it is also possible to detectjamming of the medium P, by detecting the changing amount of a positionof the separating roller 36.

(2) In the embodiment, it is configured so that a changing amount of aposition of the feeding roller 34 is detected by the angle detectingsensor 66; however, instead of the configuration, it may be aconfiguration in which the number of rotations of the feeding roller 34is detected by a rotation detecting sensor 70. Specifically, asillustrated in FIG. 19, a detecting unit 72 is provided with a rotationdetecting sensor 70 which comes into contact with the feeding roller 34,a sensor support member 76 which supports the rotation detecting sensor70 by having a swing shaft 74 as a fulcrum, and an urging unit 68.

In this configuration, a change in the number of rotations of thefeeding roller 34 is detected by the rotation detecting sensor 70. Here,since there is a change in the number of rotations of the feeding roller34 when jamming occurs in the medium P, it is possible to detect feedingdisorder of the medium P by monitoring the change in the number ofrotations, and further reduce a damage of the medium P by immediatelystopping a rotation of the feeding roller 34.

Modification Example of First to Third Embodiments

The imaging unit 44, or the detecting units 60 and 72 are applied to thescanner 10; however, instead of the configuration, the imaging unit 44,or the detecting units 60 and 72 may be applied to a printer including arecording head, as an example of a recording apparatus.

When summarizing the above descriptions, the medium feeding device 58 isprovided with the medium mounting portion 16 a for mounting the mediumP, the feeding roller 34 for feeding the medium P from the mediummounting portion 16 a, the separating roller 36 for separating themedium P by nipping the medium between the feeding roller 34 and theseparating roller, the imaging unit 44 for imaging the tip end portionPF of the medium P from a position of facing a face of the medium P onthe downstream side of the nipping position of the medium P using thefeeding roller 34 and the separating roller 36, and the control unit 30which determines whether or not there is transport disorder, byevaluating a state of a boundary between the path member 46 which formsthe medium transport path 26 and the tip end portion PF of the medium P,from the image data obtained by the imaging unit 44.

According to the above described configuration, since the medium feedingdevice 58 is provided with the imaging unit 44 for imaging the tip endportion PF of the medium P from a position of facing a face of themedium P on the downstream side of the nipping position of the medium Pusing the feeding roller 34 and the separating roller 36, and thecontrol unit 30 which determines whether or not there is transportdisorder, by evaluating a state of a boundary between the path member 46which forms the medium transport path 26 and the tip end portion PF ofthe medium P, from the image data obtained by the imaging unit 44, it ispossible to further reliably determine a state of the tip end portion PFof the medium P, and further accurately detect transport disorder of themedium P.

The control unit 30 sets the rectangular determining region R3 whichincludes at least a part of the boundary with respect to the image data,and determines whether or not there is transport disorder based on alength of the boundary in the determining region R3, that is, the edgelength. According to the configuration, it is possible to determinewhether or not there is transport disorder using an easy method.

The control unit 30 determines whether or not there is transportdisorder based on an edge angle of the boundary in the determiningregion R3, with respect to the device width direction as the mediumwidth direction which is orthogonal to the medium transport direction.According to the configuration, it is possible to determine whether ornot there is transport disorder using an easy method, and easily detectskewing as one of transport disorder, in particular.

The control unit 30 obtains averaged brightness as a value in whichbrightness of a pixel group which goes along the device width directionas the medium width direction which is orthogonal to the mediumtransport direction, along the medium transport direction from the imagedata, and the control unit 30 can obtain the first threshold value L1 asa threshold value with respect to averaged brightness, and is athreshold value for determining a present state of the medium P, and thesecond threshold value L2 as a threshold value for determining an absentstate of the medium P, and is lower than the first threshold value L1,and determines whether or not there is transport disorder based on highsand lows of the value L3 with high brightness with respect to the firstthreshold value L1, and highs and lows of the value L4 with lowbrightness with respect to the second threshold value L2, in averagedbrightness at both ends of the determining region R3 which includes atleast a part of the boundary.

According to the configuration, since the control unit 30 obtainsaveraged brightness as a value in which brightness of a pixel groupwhich goes along the medium width direction as the direction orthogonalto the medium transport direction, along the medium transport directionfrom the image data, and determines whether or not there is transportdisorder based on highs and lows of the value L3 with high brightnesswith respect to the first threshold value L1, and highs and lows of thevalue L4 with low brightness with respect to the second threshold valueL2, in averaged brightness at both ends of the determining region R3which includes at least a part of the boundary, it is possible to easilyrecognize a state of the tip end portion PF of the medium P.

In a case in which the control unit 30 determines that there istransport disorder, the feeding roller 34 is stopped. According to theconfiguration, it is possible to avoid a failure of the device which iscaused when the feeding roller 34 is operated in a state in whichtransport disorder occurred.

The feeding roller 34 which configures the feeding unit, and isrotatably driven by the feeding driving motor 32, the separating roller36 which configures the separating unit, and rotates in a driven mannerby being in contact with the feeding roller 34, and the detecting unit60 which detects a changing amount of a position of at least any one ofthe feeding roller 34 and the separating roller 36 with respect to theother roller 34 or 36 are provided. According to the configuration, itis possible to detect jamming of the medium P, by detecting the jammingwhen the feeding roller 34 or the separating roller 36 is displaced dueto an occurrence of jamming of the medium P.

The detecting unit 60 is provided with the driven roller 62 whichrotates in a driven manner by being in contact with the feeding roller34 or the separating roller 36 as a target for detecting the changingamount of a position, the roller support member 64 which rotatablysupports the driven roller 62, and can swing around a swing fulcrum, andthe angle detecting sensor 66 which detects a swing angle of the rollersupport member 64. According to the configuration, it is possible toconfigure the detecting unit 60 at a low cost, by making a structurethereof simple.

The scanner 10 is provided with the image reading unit 54 which readsthe medium P, and the medium feeding device 58. Alternatively, arecording apparatus, for example, a printer is provided with a recordinghead which performs recording on the medium P, and the medium feedingdevice 58.

The invention is not limited to the above described embodiments, and canbe variously modified in the scope of the invention which is describedin claims, and it is needless to say that those are also included in thescope of the invention.

1. An image reading apparatus comprising: a reading unit which reads amedium; a medium mounting unit on which the medium is mounted; a feedingunit which feeds the medium in a first direction from the mediummounting unit; a separating unit which separates the medium between thefeeding unit and the separating unit by nipping the medium at a nipposition; a transporting unit which is disposed between the nip positionand the reading unit, the transporting unit transports the medium fed bythe feeding unit to the reading unit; an image capturing unit which isdisposed between the nip position and the reading unit, and whichcaptures an image of a medium tip end portion from a position of facinga face of the medium; and a controller which determines whether or notthere is transport disorder by evaluating a state of a boundary betweena path member which forms a medium transport path and a medium tip endfrom the image captured by the image capturing unit, wherein, after thecontroller determines whether or not there is transport disorder, thecontroller stops the feeding of the medium when there is transportdisorder, or reads the medium by the reading unit when there is notransport disorder. 2-9. (canceled)
 10. The image reading apparatusaccording to claim 1, further comprising: a double feeding detectingsensor which detects double feeding of the medium, wherein the imagecapturing unit is disposed between the double feeding detecting sensorand the nip position.
 11. The image reading apparatus according to claim10, further comprising: a first detecting sensor which is disposed on anupstream of the reading unit, and which detects transporting of themedium by the transporting unit, wherein the image capturing unit, thedouble feeding detecting sensor and the first detecting sensor arearranged in this order with respect to the first direction.
 12. Theimage reading apparatus according to claim 11, further comprising asecond detecting sensor which is disposed between the nip position andthe image capturing unit in the first direction, and which detectsfeeding of the medium by the feeding unit.
 13. The image readingapparatus according to claim 12, wherein the second detecting sensor,the image capturing unit, the double feeding detecting sensor and thefirst detecting sensor are arranged in this order with respect to thefirst direction.
 14. An image reading apparatus comprising: a mediummounting unit on which a medium is mounted; a first roller which feedsthe medium in a first direction from the medium mounting unit; a secondroller which feeds the medium in the first direction from the mediummounting unit, the second roller being aligned with the first rolleralong a second direction that intersects with the first direction; athird roller which separates the medium by nipping the medium with thefirst roller at a first nip position; a forth roller which separates themedium by nipping the medium with the second roller at a second nipposition, the forth roller being aligned with the third roller along thesecond direction; a pair of edge guides configured to move in adirection of being close to each other or a direction of being separatedfrom each other in the second direction; a reading unit which reads themedium; a fifth roller which is disposed between the first nip positionand the reading unit, and which transports the medium fed by the firstroller to the reading unit; a sixth roller which is disposed between thesecond nip position and the reading unit, and which transports themedium fed by the second roller to the reading unit, the sixth rollerbeing aligned with the fifth roller along the second direction; a doublefeeding detecting sensor which is disposed between the first nipposition and the fifth roller in the first direction or between thesecond nip position and the sixth roller in the first direction, andwhich detects double feeding of the medium by the feeding unit; an imagecapturing unit which is disposed between the first nip position and thedouble feeding sensor or between the second nip position and the doublefeeding sensor, the image capturing unit being disposed between the edgeguides in a state of being farthest from each other in the seconddirection and the image capturing unit captures an image of a medium tipend portion from a position of facing a face of the medium; and acontroller which determines whether or not there is transport disorderby evaluating a state of a boundary between a path member which forms amedium transport path and a medium tip end from image data obtained bythe image capturing unit, wherein, after the controller determineswhether or not there is transport disorder, the controller stops thefeeding of the medium when there is transport disorder, or reads themedium by the reading unit when there is no transport disorder.
 15. Amedium feeding apparatus comprising: a medium mounting unit on which amedium is mounted; a feeding unit which feeds the medium from the mediummounting unit; a separating unit which separates the medium between thefeeding unit and the separating unit by nipping the medium at a nipposition; a processing unit which processes a predetermined process to amedium; a transporting unit which is disposed between the nip positionand the reading unit, and which transports the medium fed by the feedingunit to the reading unit; an image capturing unit which is disposedbetween the nip position and the processing unit, and which captures animage of a medium tip end portion from a position of facing a face ofthe medium; and a controller which determines whether or not there istransport disorder by evaluating a state of a boundary between a pathmember which forms a medium transport path and a medium tip end from theimage captured by the image capturing unit, wherein, after thecontroller determines whether or not there is transport disorder, thecontroller stops the feeding of the medium when there is transportdisorder, and processes the predetermined process to the medium by theprocessing unit when there is no transport disorder.